Amplified laser device using a MEMS MMA having tip, tilt and piston capability to both correct a beam profile and steer the amplified beam

Abstract

An amplified laser device is provided with one or more Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) having tip, tilt and piston capability positioned on either side of the optical amplifier to correct the profile of the beam to improve the gain performance of the optical amplifier or to compensate for atmospheric distortion while steering the amplified beam over a FOR. The MEMS MMAs may be positioned in front of, behind or on both sides of the amplifier. The MEMS MMAs can be configured to optimize the combined amplifier performance, static and time varying, and compensation for atmospheric distortion together or separately.

We claim: 
     
         1 . A laser device, comprising:
 a laser configured to generate a beam of optical radiation;   an optical amplifier configured to amplify the beam;   one or more Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) positioned on either side of the optical amplifier to receive the beam, said one or more MMAs comprising a plurality of mirrors independently responsive to command signals to tip and tilt about first and second axes, respectively, and to piston in translation along a third axis in three degrees-of-freedom (3DOF) to correct a profile of the beam and to steer the beam; and   a controller configured to generate command signals to actuate the mirrors on at least one said MEMS MMA to piston the mirrors to correct the profile of the beam to correct a spatial intensity profile and to tip and tilt the mirrors to correct a cross-section of the beam to improve the gain performance of the optical amplifier to steer the beam over a field-of-regard (FOR).   
     
     
         2 . The laser device of  claim 1 , wherein the mirrors on at least one said MEMS MMA are responsive to command signals to piston the mirrors to compensate for atmospheric distortion and to tip and tilt the mirrors to steer the beam. 
     
     
         3 . The laser device of  claim 1 , wherein the mirrors on at least one said MEMS MMA have dielectric coatings configured to reflect at different wavelengths. 
     
     
         4 . The laser device of  claim 1 , wherein the mirrors on at least one said MEMS MMA are responsive to command signals to separate the beam into a plurality of independently steered and profile corrected beams. 
     
     
         5 . The laser device of  claim 1 , wherein the mirrors on at least one said MEMS MMA are further responsive to command signals to tip and tilt to focus the beam into a spot-beam or to add optical power to the beam. 
     
     
         6 . A laser device, comprising:
 a laser configured to generate a beam of optical radiation;   an optical amplifier configured to amplify the beam;   a single Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) positioned in front of the optical amplifier to receive the beam, said one or more MMAs comprising a plurality of mirrors independently responsive to command signals to tip and tilt about first and second axes, respectively, and to piston in translation along a third axis in three degrees-of-freedom (3DOF) to correct a profile of the beam and to steer the beam; and   a controller configured to generate command signals to piston the mirrors to correct the profile of the beam to correct a spatial intensity profile and to tip and tilt the mirrors to correct a cross-section of the beam to optimize the gain performance of the optical amplifier without regard for atmospheric distortion while steering the beam over a field-of-regard (FOR).   
     
     
         7 . The laser device of  claim 6 , further comprising a sensor configured to monitor the output power level of the optical amplifier and feedback the sensed level to the controller, wherein the controller is configured to generate command signals to compensate for time varying fluctuations in the amplifier's output power level. 
     
     
         8 . A laser device, comprising:
 a laser configured to generate a beam of optical radiation;   an optical amplifier configured to amplify the beam;   a single Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) positioned in front of the optical amplifier to receive the beam, said one or more MMAs comprising a plurality of mirrors independently responsive to command signals to tip and tilt about first and second axes, respectively, and to piston in translation along a third axis in three degrees-of-freedom (3DOF) to correct a profile of the beam and to steer the beam;   a wavefront sensor system configured to measure atmospheric distortion,   a controller configured to generate command signals to piston the mirrors to correct a spatial intensity profile and to tip and tilt the mirrors to correct a cross-section of the beam to improve the gain performance of the optical amplifier and to piston the mirrors to correct the wavefront of the beam to compensate for atmospheric distortion while tipping and tilting the mirrors to steer the beam over a field-of-regard (FOR).   
     
     
         9 . The laser device of  1 , wherein a single said MEMS MMA is positioned in front of the optical amplifier, further comprising:
 a fixed mirror having a first conic section oriented along an optical axis that redirects the steered beam away from the optical axis to scan a circular pattern in a two-dimensional FOR; and   wherein the optical amplifier comprises a ring amplifier including one or more pumps configured to pump a gain medium in the form of a ring, said ring amplifier configured such that said beam passes through the gain medium one or more times to amplify the beam while preserving the steering of the beam over the FOR.   
     
     
         10 . The laser device of  claim 9 , further comprising a focusing element configured to focus the beam into a spot-beam on the fixed mirror, said focusing element selected from one of a lens, additional tip, tilt and piston of the mirrors, and off-axis sections of a parabolic mirror. 
     
     
         11 . A laser device, comprising:
 a laser configured to generate a beam of optical radiation;   an optical amplifier configured to amplify the beam;   a single Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) positioned behind the optical amplifier to receive the beam, said one or more MMAs comprising a plurality of mirrors independently responsive to command signals to tip and tilt about first and second axes, respectively, and to piston in translation along a third axis in three degrees-of-freedom (3DOF) to correct a profile of the beam and to steer the beam;   a wavefront sensor system configured to measure atmospheric distortion,   a controller configured to generate command signals to piston the mirrors to optimize compensation for atmospheric distortion without regard for the gain performance of the optical amplifier while tipping and tilting the mirrors to steer the amplified beam over a field-of-regard (FOR).   
     
     
         12 . A laser device, comprising:
 a laser configured to generate a beam of optical radiation;   an optical amplifier configured to amplify the beam;   first and seconds Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) positioned in front of and behind the optical amplifier, respectively, to receive the beam, said one or more MMAs comprising a plurality of mirrors independently responsive to command signals to tip and tilt about first and second axes, respectively, and to piston in translation along a third axis in three degrees-of-freedom (3DOF) to correct a profile of the beam and to steer the beam;   
       a wavefront sensor system configured to measure atmospheric distortion,
 a controller configured to generate command signals for the first MEMS MMA to piston the mirrors to correct a spatial intensity profile and to tip and tilt the mirrors to correct a cross-section of the beam to optimize the gain performance of the optical amplifier and to generate command signals for the second MEMS MMA to piston the mirrors to optimize compensation for atmospheric distortion and to tip and tilt mirrors to steer the beam over a field-of-regard (FOR). 
 
     
     
         13 . The laser device of  claim 12 , wherein the first and second MEMS MMA are different sections of a common MEMS MMA, wherein the beam reflected off of the first MEMS MMA is reflected back-and-forth through the optical amplifier to the second MEMS MMA. 
     
     
         14 . A laser device, comprising:
 a laser configured to generate a beam of optical radiation;   an optical amplifier configured to amplify the beam;   one or more Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) of which one is positioned in front of the optical amplifier to receive the beam, said one or more MMAs comprising a plurality of mirrors independently responsive to command signals to tip and tilt about first and second axes, respectively, and to piston in translation along a third axis in three degrees-of-freedom (3DOF) to correct a profile of the beam and to steer the beam;   a wavefront sensor system configured to measure atmospheric distortion;   a controller configured to generate command signals to actuate the mirrors to correct the profile of the beam to correct a spatial intensity profile and a cross-section of the beam to improve the gain performance of the optical amplifier and to correct a wavefront of the beam to compensate for atmospheric distortion and command signals to steer the beam over a field-of-regard (FOR)   a sensor configured to monitor the output power level of the optical amplifier and feedback the sensed level to the controller, wherein the controller is configured to generate command signals to compensate for time varying fluctuations in the amplifier's output power level.   
     
     
         15 . A laser device, comprising:
 a laser configured to generate a beam of optical radiation;   an optical amplifier configured to amplify the beam;   first and second Micro-Electro-Mechanical System (MEMS) Micro-Mirror Arrays (MMAs) positioned in front of and in back of the optical amplifier, respectively, to receive the beam, said one or more MMAs comprising a plurality of mirrors independently responsive to command signals to tip and tilt about first and second axes, respectively, and to piston in translation along a third axis in three degrees-of-freedom ( 3 DOF) to correct a profile of the beam and to steer the beam;   a wavefront sensor system configured to measure atmospheric distortion;   a controller configured to generate command signals for the first MEMS MMA to piston the mirrors to correct a spatial intensity profile and to tip and tilt the mirrors to correct a cross-section of the beam to optimize gain performance of the optical amplifier and to generate command signals for the second MEMS MMA to piston the mirrors to optimize compensation for atmospheric distortion and to tip and tilt mirrors to steer the beam over a field-of-regard (FOR).   
     
     
         16 . The laser device of  claim 15 , wherein the first and second MEMS MMA are different sections of a common MEMS MMA, wherein the beam reflected off of the first MEMS MMA is reflected back-and-forth through the optical amplifier to the second MEMS MMA.